Here are a few more I found:
In regards to the Operative's Trick Attack:
In the Core Book: The DC for a Trick attack is 20 + your target's CR.
In the Beginner box: The DC for a Trick attack is a flat 20.
In the Core Book: If you succeed you add a 1d4 to your damage and the target is flat-footed.
In the Beginner Box: If you succeed you add a +2 to your hit and add a 1d4 to your damage.(I know flat-footed gives a -2 to your opponent's AC so it's basically the same?)
In the Corebook: Ghost gives you a +4 bonus to your trick attack if you use Stealth.
In the Beginner Box: It gives you a +3 instead.
There is also a Starfinder FAQ that says it only gives a +1.
In regards to the Operative class:
In the Core book: Operatives can use Sniper Weapons
In the Beginner Box: Operatives can only use Basic Melee and Small Arms.(I assume it's this way because the players might not run into any Sniper weapons in the packaged adventure, I haven't read it yet)